Air Conditioning Cushion for Wheelchair

ABSTRACT

A seat cushion for use in a wheel chair includes a foam pad contoured to the anatomy of a user positioned thereon and has an indentation in the middle thereof, which receives and drains incontinence fluid from the user. The foam pad encloses an air channel between the indentation and at least one side of the foam pad. A fan housed inside the pad pushes air through the air channel, into the indentation and onto the user. Alternatively, the seat cushion may house an air conditioner to circulate cooled air to the skin of the user.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on U.S. Provisional Patent Application Ser. No. 60/816,834, filed Jun. 27, 2006, and claims priority based on the earlier filed provisional patent application, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

This invention relates to a seat cushion; more specifically, a seat cushion that may be used in a wheelchair to drain incontinence fluid and deliver conditioned air to the skin of the user.

2. Description of the Prior Art

U.S. Pat. No. 4,923,248 teaches a cooled seat cushion having a bottom and a back. Both the bottom and the back have a series of air passageways forming a plenum. This plenum is fed air from a Peltier unit which is attached to a DC power source, preferably a cigarette lighter in a car. The air passageways of the plenum are constructed of wound metallic coils; the passageways crisscross throughout the interior of both the seat bottom and back. The Peltier unit feeds the plenum air at the seat cushion's bottom, between the user's legs, or at the juncture between the bottom and the back, where it traverses the seat cushion and exits at the top of the seat back. The chilled air, in traversing the plenum, cools the seat cushion.

Seat constructions having a recessed region allowing incontinence fluids from a user to drain off are common to the field. Additionally, augmenting user comfort with an additional cushion in a chair is also common in the field.

However, the above described systems suffer from the drawbacks of an inability to combine functions of cooling and handling incontinence material, and utilization of an insufficient and weak cooling system; thus there is a need for a seat cushion that can convectively cool the skin of a user, receive and remove the byproducts of incontinence, and provide additional, comfortable support.

SUMMARY OF THE INVENTION

The present invention is directed to a seat cushion that delivers air to a user and removes moisture. In one embodiment of the invention, an indentation is formed into the center of the top of a foam pad and an air channel is formed through the foam pad, communicating between one of the sides of the foam pad and the indentation. In the air channel a cavity is formed and a chamber subassembly is inserted therein. This chamber subassembly has apertures on two of the sides and serves to maintain the viability of the channel after a user compresses the foam pad. Air naturally circulates through the air channel, through the chamber assembly, and into the indentation, which is filled with a permeable mesh. This permeable mesh insert allows the air to flow freely, while maintaining a comfortable level of support for the user, with the added benefit of allowing incontinence liquid to flow out through the insert drain through the indentation.

In another embodiment, the same configuration is used, except that the chamber subassembly includes an air circulating device, such as a fan, which forces room-temperature air into the indentation. In a third embodiment, an air conditioner or air cooling unit is integrated into the foam pad, in conjunction with the fan, with both preferably mounted inside the foam pad so that the air channel receives air conditioned by the air conditioner and distributes it into the indentation.

It is an object of this invention to augment the comfort and support of one sitting, especially one sitting for prolonged period in a wheelchair.

It is further an object of this invention to drain incontinence fluid released from a body of a user to avoid unsanitary and moist conditions on the skin of the user and to mitigate the risks of consequent skin breakdown.

It is another object of this invention to deliver conditioned air to the skin of the user to cool and dry the skin of the user to reduce the formation of skin ulcers and pressure sores.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a seat cushion embodiment constructed in accordance with the present invention and including a chamber subassembly.

FIG. 2 is a perspective view of a foam pad shown in FIG. 1.

FIG. 3 is a cross sectional view, taken along line 3-3 of FIG. 2.

FIG. 4 is a side view of the permeable mesh, with the arrows representing the direction of the flow of air.

FIG. 5 is an elevated perspective view of the chamber subassembly shown in FIG. 1, with the arrows representing the direction of the flow of air.

FIG. 6 is a perspective view of the bottom of the chamber subassembly with the mounting plate removed.

FIG. 7 is a perspective view of the seat cushion in a wheelchair application.

FIG. 8 is an exploded isometric view of the seat cushion embodiment that includes an integrated air conditioner.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, FIG. 1 shows a seat cushion comprising a foam pad 10 formed with a metal mold; however, other molds or methods of construction could be used to achieve the shape and function of this foam pad 10. The foam pad 10 is constructed of foam that gently compresses to comfortably support the user and is coated with a material that is substantially impervious to liquid. The foam pad 10 further has a top 12, which is contoured to the anatomy of a user when the user is sitting on the seat cushion, a bottom 14, a side 16, a back side 18, a front side 20, and a side 22.

Formed into the top 12 of the foam pad 10 is an indentation 24, which, in the preferred embodiment, has a roughly concave surface 26. However, alternatively shaped surfaces that comfortably support the user, which receive and drain incontinence fluids, will suffice. The indentation 24 is sloped away from the front side 20 and towards the back side 18, such that fluids received into the indentation flow on the concave surface 26 towards the back side 18, evacuating the fluids from the skin of the user. Formed in the middle of the indentation 24, protruding up from the concave surface 26, is a support protrusion 28.

An insert 30 having an outer layer 32, inner layer 34, and an air barrier 36, fills the indentation 24. The inner layer 34 has an opening 35 in the middle roughly the size of the support protrusion 28. The inner layer 34 fits snugly around the support protrusion 28 and against the concave surface 26 of the indentation 24 such that the support protrusion 28 keeps the inner layer 34 in place. This arrangement ensures that the area around the support protrusion remains a viable region through which fluid may permeate towards the back side 18.

The outer layer 32, which rests along the top of the support protrusion 28 and the inner layer 34, is dimensioned roughly the same as the indentation 24. The outer layer 32 makes a top for the indentation 24. To maintain the ability of the indentation 24 to receive incontinence fluid and circulate air, the outer layer 32 and the inner layer 34 of the insert are comprised of permeable mesh 38, illustrated in FIG. 4. The permeable mesh 38 has a first hide 40, a second hide 42, and a multiplicity of resilient fibers 44 in between that bias the first hide 40 and the second hide 42 apart. When in use, the fibers resiliently compress. Thus, when the permeable mesh 38 is compressed, the fibers 44 flex and provide a force to oppose the compression. There is space between the fibers 44 so that even when the fibers 44 are compressed, the space between them remains vacant, allowing air and fluid to permeate through in all directions. These fibers 44 also add stiffness to the insert 30.

Constructing the insert 30 with the permeable mesh 38 ensures that the insert 30 provides support for the user in the indentation 24, but does not become a sponge that holds the incontinence fluid and blocks air circulation. Instead, the permeable mesh 38 of the insert 30 allows the incontinence fluids to flow between the fibers 44 along the concave surface 26, towards back side 18, while not significantly impeding air circulation in the indentation 24.

FIG. 3 exposes the interior of the foam pad 10 in a cross-section view, along line 3-3 from FIG. 2. As shown in FIG. 3, an air channel 46 is formed into the foam pad 10. The air channel 46 has entrance holes 46A formed into the front side 20 of the foam pad 10 and an exit 46B formed into the concave surface 26 of the indentation 24. Intersecting the air channel 46 is a cavity 48. The cavity 48 is formed into the bottom 14 of the foam pad 10; however, in alternative embodiments, the cavity 48 may be formed in one of the sides 16, 18, 20, or 22.

A chamber subassembly 50, as shown in FIG. 1, fits snugly inside the cavity 48. The chamber subassembly 50, as shown in FIG. 5, has a preferably substantially rectangular base 51, though alternative shapes are contemplated. The chamber subassembly 50 also includes a shell 52 preferably made of a sturdy but slightly flexible material such as certain plastics, thermoplastic olefins, or other composite materials, and a mounting plate 53 that fits on the rectangular base 51. The mounting plate 53 attaches to the bottom 12 of the foam pad 10, shown in FIG. 1, holding the chamber subassembly 50 in place in the cavity 48 (the cavity 48 is shown in FIG. 3). The shell 52 is shaped to have a bulge 54, and there are apertures in the shell 52 on both sides of the bulge 54. These are the intake apertures 56 and the outlet apertures 57. The sturdiness of the plastic shell 52 ensures that neither the cavity 48 nor the air channel 46 collapse when a user sits on the foam pad 10, while the shape of the shell 52 allows the top 12 of the foam pad 10 to remain shaped to the anatomy of the user when the user is seated on the seat cushion.

As shown in FIG. 6, in one embodiment a fan 58 is mounted inside the shell 52 and powered by a battery pack 59 so that the fan 58 pulls air through the intake apertures 56 and pushes it out the outlet apertures 57. Other embodiments may not require the addition of the fan 58, relying on natural convection of air through the shell 52, or an external method of pushing air through the chamber subassembly 50.

The intake apertures 56 and outlet apertures 57 on the shell 52 of the chamber subassembly 50 are aligned with the air channel 46 and secured in place with the mounting plate 53. The chamber subassembly 50 is inserted into the bottom 14 of the foam pad 10 as shown in FIG. 1. The air, once pushed through the outlet apertures 56, travels to the exit of the air channel 46B. The stream of air then, instead of flowing as a condensed stream into the user, collides with the air barrier 36, thus disbursing the air in the indentation 24, throughout the insert 30.

The majority of wheelchair use is done in-doors, where the air temperature and humidity are controlled by the building's air conditioning unit. The chamber subassembly 50, when installed into the cavity 48 as depicted in FIG. 1, delivers this conditioned ambient air to the skin of the user. Thus the relatively low humidity and low temperature ambient air is delivered to the indentation 24 to ventilate the skin of the user, convecting heat away and evaporating moisture. This promotes cool dry skin conditions adverse to the formation of skin ulcers.

Further, an air conditioner 60 may be used in addition to, or instead of, the chamber subassembly 50 as shown in FIG. 8. The air conditioner 60 is described in U.S. Pat. No. 6,240,742, the details of which are incorporated herein by reference. The air conditioner 60 employs a method of evaporating and condensing a fluid to chill, with the option to heat, a fin arrangement (not shown) across which air is forced which is located in the path to the skin of the user; however, unlike other air chillers, this air conditioner 60 is small enough to be mounted inside the foam pad 10. Further, the air conditioner 60 functions utilizing evaporative cooling between sealed low pressure chambers, combined with absorptive air pressure reduction technology, and thus does not require a bulky or heavy battery. It merely requires enough battery power to control the operation of a valve.

In the preferred embodiment, the air conditioner 60 fits snugly in the cavity 48. Thus the air conditioner 60 chills or, if desirable, heats air, which then flows to the indentation 24 where it collides with the air barrier 36, which disburses it throughout the insert 30. At night, or when the seat cushion is not in use, the air conditioner 60 may be removed to recharge its evaporative cooling system (not shown).

As shown in FIG. 1, a cover 64 envelops or fits over at least a portion of the foam pad 10 and preferably covers all of the foam pad 10. The cover 64 is partially constructed of the permeable mesh 38, illustrated in FIG. 4. When the user sits on the cushion, the permeable mesh 38 of the cover 64 compresses, but remains air and liquid permeable because the multiplicity of resilient fibers 44 between the first hide 40 and the second hide 42 flex and exert reactionary force. Further, these fibers 44 add a pressure redistribution function to the cover 64, increasing the support provided to the user. In one embodiment, the permeable mesh 38 comprises a side 65 of the cover 64, which fits over the back side 18 of the foam pad 10, for allowing air to ventilate the indentation 24. In other embodiments, the permeable mesh 38 could also comprise a portion 67 of the cover 64 over the front side 20 of the foam pad 10, to allow increased flow of air to the chamber subassembly 50 or the air conditioner 60; the permeable mesh 38 could also comprise the cover 64 in its entirety. Areas of the cover 64 not comprised of the permeable mesh 38 are preferably made of a breathable fabric suitable for comfortably supporting a user.

Thus, the cover 64 allows air to circulate into the air channel 46 into the chamber subassembly 50, and/or air conditioner 60, depending on the embodiment, and throughout the indentation 24. Further, even when compressed by a user, the permeable mesh 38 of the cover 64 remains liquid permeable, allowing incontinence fluid flowing from out of the indentation 24 to traverse the cover and be evacuated from the seat cushion.

Illustrated in FIG. 7, the preferred application of this seat cushion is in a wheelchair, to increase the health and welfare of a prolonged, continuous user.

Thus it is seen that the apparatus of the present invention readily achieves the ends and advantages mentioned, as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims. Although there have been described particular embodiments of the present invention of a new and useful ventilated seat cushion, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the appended claims. 

1. A seat cushion comprising: a foam pad comprising a top upon which a user may sit, an opposed bottom, and a plurality of sides extending between the top and bottom; an indentation in the top of the foam pad and having a substantially concave surface for receiving incontinence fluid and circulating air; and an insert fitting in the indentation for supporting the user while the user sits on the seat cushion and allowing incontinence fluid to flow to the concave surface of the indentation.
 2. The seat cushion of claim 1, wherein the insert comprises a permeable mesh.
 3. The seat cushion of claim 2, wherein the permeable mesh comprises: a first hide; a second hide; and a multiplicity of fibers between the first hide and the second hide, so that the fibers resiliently compress between the first hide and second hide when the user sits on the seat cushion.
 4. The seat cushion of claim 1, wherein the foam pad further comprises: a support protrusion defined in the foam pad, located on the concave surface of the indentation, for supporting the insert.
 5. The seat cushion of claim 4, wherein the insert further comprises an outer layer supported by the support protrusion; and an inner layer attached to the outer layer, fitting between the outer layer and the concave surface of the indentation, and disposed about the support protrusion, for maintaining air circulation and reception of incontinence fluid in the indentation.
 6. The seat cushion of claim 5, wherein the insert further comprises a permeable mesh.
 7. (canceled)
 8. The seat cushion of claim 1, further comprising: an air channel defined in the foam pad, having a first end communicated with the indentation, and a second end communicated with at least one of the plurality of sides.
 9. The seat cushion of claim 8, further comprising: a cavity defined in the foam pad, intersecting the air channel.
 10. (canceled)
 11. The seat cushion of claim 9, further comprising: a chamber subassembly located in the cavity, the chamber subassembly comprising a shell having a plurality of apertures aligned with the air channel.
 12. The seat cushion of claim 11, wherein the chamber subassembly further comprises: a fan attached to the shell, for forcing air through the apertures.
 13. The seat cushion of claim 11 further comprising: an air barrier attached to the insert where the air channel communicates with the indentation, for disbursing the air that comes through the air channel.
 14. The seat cushion of claim 11, further comprising: an air cooling unit comprising an outlet operationally connected to the chamber subassembly, for providing cooled air to the chamber subassembly.
 15. The seat cushion of claim 1 further comprising: a cover fitting over at least a portion of the foam pad, the cover comprising a permeable mesh, for protecting the foam pad and allowing air and fluid to enter and exit the indentation.
 16. The seat cushion of claim 15, wherein the permeable mesh comprises: a first hide; a second hide; and a multiplicity of fibers located between the first hide and the second hide, so that the fibers resiliently bias the first hide and second hide apart for enhancing ventilation.
 17. The seat cushion of claim 1 further comprising an air conditioner operatively attached to the foam pad to circulate conditioned air about at least a portion of the user who sits on the seat cushion.
 18. An apparatus for ventilating a seat cushion, the apparatus comprising a shell having a plurality of apertures; and a fan operatively positioned inside the shell for forcing air through the apertures and throughout at least a portion of the seat cushion.
 19. The apparatus of claim 18 further comprising an air cooling unit comprising an air outlet operationally connected to the shell for cooling the air the fan forces throughout at least a portion of the seat cushion.
 20. A seat cushion for use with a wheelchair comprising: a foam pad having a top contoured to the anatomy of a user when the user is sitting on the foam pad, an opposed bottom, and a plurality of sides connecting the top and the bottom; and an air circulating device integrated into at least a portion of the foam pad to circulate air to at least a portion of a user, when the user sits on the foam pad; and an indentation comprising a surface defined in the foam pad for receiving incontinence fluids from the user and receiving air from the air circulating device.
 21. (canceled)
 22. The seat cushion of claim 20 further comprising: an insert fitting in the indentation for supporting the user while allowing incontinence fluid to flow to the indentation.
 23. (canceled)
 24. The seat cushion of claim 22, wherein the insert further comprises: a mesh outer layer; and a mesh inner layer attached to the mesh outer layer and fitting between the mesh outer layer and the surface of the indentation, the mesh inner layer being disposed about the support protrusion, for maintaining air circulation and reception of incontinence fluid in the indentation.
 25. The seat cushion of claim 24 further comprising: an air channel defined in the foam pad, having a first end in communication with the indentation and a second end in communication with at least one of the plurality of sides.
 26. The seat cushion of claim 25 further comprising: an air barrier attached to the mesh outer layer of the insert where the air channel communicates with the indentation, for disbursing the air received through the air channel; and a cavity defined in the foam pad, having a mouth opening into the foam pad and formed such that air channel is in communication with the cavity, wherein the air circulating device is located in the cavity.
 27. (canceled)
 28. (canceled)
 29. The seat cushion of claim 20, wherein the air circulating device comprises a fan.
 30. The seat cushion of claim 20, wherein the air circulating device comprises an air conditioner.
 31. The seat cushion of claim 20 further comprising: a permeable mesh cover fitting over at least a portion of the foam pad.
 32. (canceled) 